Acetone is an important industrial raw material as well as biomarker in medical diagnosis.The detection of acetone has great significance for safety and health.However,high selectivity and low concentration(ppb level)...Acetone is an important industrial raw material as well as biomarker in medical diagnosis.The detection of acetone has great significance for safety and health.However,high selectivity and low concentration(ppb level)detection remain challenges for semiconductor gas sensor.Herein,we present a novel sensitive material with bimetallic PtCu nanocrystal modified on WO3·H2O hollow spheres(HS),which shows high sensitivity,excellent selectivity,fast response/recovery speed and low limit of detection(LOD)to acetone detection.Noteworthy,the response(Ra/Rg)of WO3·H2O HS sensor increased by 9.5 times after modification with 0.02%bimetallic PtCu nanocrystals.The response of PtCu/WO3·H2O HS to 50 ppm acetone is as high as 204.9 with short response/recovery times(3.4 s/7.5 s).Finally,the gassensitivity mechanism was discussed based on gas sensitivity test results.This research will offer a new route for high efficient acetone detection.展开更多
In order to detect low concentrations of volatile organic compounds (VOCs) for the early diagnosis of lung cancer, sensors based on hollow spheres of In_(2)O_(3) were prepared through the soft template method. Ag nano...In order to detect low concentrations of volatile organic compounds (VOCs) for the early diagnosis of lung cancer, sensors based on hollow spheres of In_(2)O_(3) were prepared through the soft template method. Ag nanoparticle decorated In_(2)O_(3) composites were synthesized via dipping and annealing. The microstructure, phase composition, element distribution, and state of Ag were analyzed by the scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The gas sensing tests showed that Ag-In_(2)O_(3) sensors had the highest response to isopropanol at 300 ℃. The best response of Ag-In_(2)O_(3) composite sensor was 5.2, which had a significant improvement compared with only In_(2)O_(3). Moreover, the response and recovery time of Ag-In_(2)O_(3) composite sensor was significantly shortened. The improved sensing properties of Ag-In_(2)O_(3) composite sensor could be attributed to the Schottky barrier created at Ag-In_(2)O_(3) interface and catalytical effect of Ag.展开更多
Semiconductor metal oxides have attracted wide attention in the area of gas sensor due to that they have unique advantages in the rapid and accurate detection of harmful gases.A simple strategy is to synthesize porous...Semiconductor metal oxides have attracted wide attention in the area of gas sensor due to that they have unique advantages in the rapid and accurate detection of harmful gases.A simple strategy is to synthesize porous NiO hollow microspheres via a simple hydrothermal method with trisodium citrate as structure guide agent is presented in this paper,and the shell of the microsphere is composed of porous and lamellar assembly units.The cavity proportion can be adjusted by changing the amount of trisodium citrate.A reasonable mechanism was proposed to explain the formation of porous NiO hollow microspheres.As a gas-sensing material,porous NiO hollow microspheres show excellent gas selectivity and rapid response recovery time for n-butyl alcohol gas.When the content of trisodium citrate was 0.10 g,the synthesized hollow sphere NiO had the highest response value(25.6)to 100×10^(-6) of n-butyl alcohol at 300℃ and the response and recovery times were only 68 and 10 s.展开更多
基金the financial supports from the National Natural Science Foundation of China(Nos.51702212,51802195,31701678,61671284)Science and Technology Commission of Shanghai Municipality(Nos.18511110600,19ZR1435200)+1 种基金Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-07-E00015)Program of Shanghai Academic Research Leader(No.19XD1422900)。
文摘Acetone is an important industrial raw material as well as biomarker in medical diagnosis.The detection of acetone has great significance for safety and health.However,high selectivity and low concentration(ppb level)detection remain challenges for semiconductor gas sensor.Herein,we present a novel sensitive material with bimetallic PtCu nanocrystal modified on WO3·H2O hollow spheres(HS),which shows high sensitivity,excellent selectivity,fast response/recovery speed and low limit of detection(LOD)to acetone detection.Noteworthy,the response(Ra/Rg)of WO3·H2O HS sensor increased by 9.5 times after modification with 0.02%bimetallic PtCu nanocrystals.The response of PtCu/WO3·H2O HS to 50 ppm acetone is as high as 204.9 with short response/recovery times(3.4 s/7.5 s).Finally,the gassensitivity mechanism was discussed based on gas sensitivity test results.This research will offer a new route for high efficient acetone detection.
基金This work is supported by the National Natural Science Foundation of China(No.51872254)the National Key R&D Program of China(No.2017YFE0115900)+3 种基金the Outstanding Youth Foundation of Jiangsu Province of China(No.BK20211548)The authors also thank the European Regional Development Fund(ERDF)and the Walloon Region of Belgium through the Interreg V France-Wallonie-Vlaanderen program,PATHACOV project(No.1.1.297)the Micro project co-funded by the European Regional Development Fund(ERDF),and Wallonia,Belgium(No.675781-642409)This work is also supported by the CommunautéWallonie-Bruxelles via the WBI-MOST-China(No.SUB/2019/430254).
文摘In order to detect low concentrations of volatile organic compounds (VOCs) for the early diagnosis of lung cancer, sensors based on hollow spheres of In_(2)O_(3) were prepared through the soft template method. Ag nanoparticle decorated In_(2)O_(3) composites were synthesized via dipping and annealing. The microstructure, phase composition, element distribution, and state of Ag were analyzed by the scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The gas sensing tests showed that Ag-In_(2)O_(3) sensors had the highest response to isopropanol at 300 ℃. The best response of Ag-In_(2)O_(3) composite sensor was 5.2, which had a significant improvement compared with only In_(2)O_(3). Moreover, the response and recovery time of Ag-In_(2)O_(3) composite sensor was significantly shortened. The improved sensing properties of Ag-In_(2)O_(3) composite sensor could be attributed to the Schottky barrier created at Ag-In_(2)O_(3) interface and catalytical effect of Ag.
基金financially supported by the Natural Science Basic Research Plan in Shaanxi Province of China(No.2018JM2015)the Fundamental Research Funds for the Central Universities(No.3102017jc01001)the National Key Research and Development Program of China(No.2017YFC0211500)。
文摘Semiconductor metal oxides have attracted wide attention in the area of gas sensor due to that they have unique advantages in the rapid and accurate detection of harmful gases.A simple strategy is to synthesize porous NiO hollow microspheres via a simple hydrothermal method with trisodium citrate as structure guide agent is presented in this paper,and the shell of the microsphere is composed of porous and lamellar assembly units.The cavity proportion can be adjusted by changing the amount of trisodium citrate.A reasonable mechanism was proposed to explain the formation of porous NiO hollow microspheres.As a gas-sensing material,porous NiO hollow microspheres show excellent gas selectivity and rapid response recovery time for n-butyl alcohol gas.When the content of trisodium citrate was 0.10 g,the synthesized hollow sphere NiO had the highest response value(25.6)to 100×10^(-6) of n-butyl alcohol at 300℃ and the response and recovery times were only 68 and 10 s.
